[Serum angiotensin converting enzyme in the diagnosis of sarcoidosis and other lung diseases].

The serum angiotensin-converting enzyme activity (ACE) was studied in 198 patients (116 had sarcoidosis and 82 pulmonary diseases with sarcoidosis-like X-ray picture). Rise of ACE activity in sarcoidosis patients was clearly associated with the process phase (93% in active sarcoidosis and 35.7% in nonactive). Rise of serum ACE activity was found in 46.3% of the patients having sarcoidosis-like diseases (in 41% with tuberculosis 56.3% with nonspecific inflammatory diseases and also in patients with fibrosing alveolitis, histiocytosis X and pneumoconiosis). Though the blood serum ACE activity has a high rate of the increase in sarcoidosis, this test should be considered only in the general complex of differential diagnosis signs. This can be explained by a sufficiently high probability of ACE activity rise in all diseases that most commonly require differentiation with sarcoidosis.